For me, dropping the cleveland in was just that simple, dropping it in. My rig already had a bodylift when I bought it, so when I decided to run a cleveland it fit in like stock. With my 3" bodylift I can use a 1" carbspacer and a 4" tall K&N filter and close my stock hood without hitting anything, the cleveland actually has a shorter deck height than the windsor, not much though.
Before I swapped to an aluminum radiator, I had the stock bronco rad, so for the lower hose I used a piece of pvc pipe to reroute the bottom hose to the correct side, just splice it in between the rad outlet and water pump outlet. Get some universal fit radiator flex hose from any parts store to make your own custom hose.
I use a Lokar throttle pedal and cable assembly and have no clearance issues.
If you plan on wheeling, then yes a rear sump pan is necessary. I severly smashed my stock pan before I swapped to a rear sump. I used the 351m/400 pan from a 4x4 truck, got it from a local junkyard. If you want a new pan, then you can try a Mustang Fox body pan for a 351c, they are rear sump, but I think you will still end up hitting the front diff with that pan.
The FC3 headers are great and fit very well, you just need to space up the passenger side of the engine, because the header sits right on top of the framerail. I spaced mine about 1/2" and have had no problems.
You can check my gallery for pics of my setup, or email me with any questions.
Congratulations on an excellent engine choice, I will never use anything else in my bronco. Except for a stroker cleveland of course.